Two silicon optical modulators realizable with a fully compatible bipolar process

In this paper, we describe two different kinds of silicon optical modulators both integrated into a silicon on silicon optical channel waveguide which can be realized using a standard bipolar process. The possibility of using standard, well-known technology presents several advantages with respect to III-V optoelectronics. The first device presented is based on a three-terminal active device and exploits the plasma dispersion effect to achieve the desired modulation. The active device used is a bipolar mode field effect transistor; we show how the introduction of the third control terminal introduces some definite advantages with respect to commonly p-i-n driven modulators. The second is an electrically controlled Bragg reflector. In this case, although controlled by a p-i-n diode, fast switching speed is achieved because lower injection levels are required. Numerical simulations and preliminary experimental results are presented on both devices.